


Princess?

by Impala_Cherry_Trickster



Series: Merlin Prompts [50]
Category: Merlin (TV)
Genre: Always a Girl! Merlin, Arthur Knows About Merlin's Magic (Merlin), Explicit Sexual Content, F/F, F/M, Female Arthur, Female Merlin (Merlin), First Time, Gender or Sex Swap, Merlin is a Little Shit, Pining Gwaine (Merlin), Protective Gwaine (Merlin), Spells & Enchantments, Threesome - F/F/M, Top Arthur
Language: English
Status: Completed
Published: 2020-07-19
Updated: 2020-07-19
Packaged: 2021-03-05 03:20:09
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,937
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/25377553
Author URL: https://archiveofourown.org/users/Impala_Cherry_Trickster/pseuds/Impala_Cherry_Trickster
Summary: Arthur's not impressed when he gets hit by a curse, but it's Merlin and Gwaine that have to deal with it.
Relationships: Gwaine/Merlin (Merlin), Gwaine/Merlin/Arthur Pendragon (Merlin), Merlin/Arthur Pendragon (Merlin)
Series: Merlin Prompts [50]
Series URL: https://archiveofourown.org/series/1706692
Comments: 15
Kudos: 190





	Princess?

**Author's Note:**

> Prompt for Weirdhead498, enjoy!

‘I guess I should stop calling him Princess.’ Gwaine remarked, Merlin hitting his shoulder. He snorted with laughter, nudging her back as they watched the recently-turned-female King of Camelot. The three of them had been on a mission to recover an artifact that Uther had used to help track Dragons, when a Sorcerer had attacked Merlin. She had been more than happy with that, teasing and encouraging, until Arthur just had to try and play the hero and jump in front of the curse.

‘What do we do? The King of Camelot is…’ Arthur spun to them, pacing across in his now-oversized armour, a mess of blonde hair and a delicate face that showed his annoyance.

‘Change me back.’ He, she, the King demanded. Merlin paused, looking to Gwaine, then back to Arthur.

‘It’ll take me at least a couple of days to perfect the spell, Sire.’ She may be an accomplished Witch, teaching both her and Morgana how to control their gifts, but it did not mean she was able to turn Arthur back.

‘Then we make Camp. I cannot go back to Camelot in this… weak form.’ Gwaine tensed, but Merlin was used to the jibes against her gender. She snorted, before looking across to the rocky cliffs that might provide a cave for shelter.

‘Come along then, Arthur.’ Merlin began to walk off in the direction of their new home, Gwaine by her side, but Arthur halted.

‘Merlin, I…’ She halted, looked over her shoulder. The King looked thoroughly defeated, shoulders slumping in defeat.

‘I can’t hold this armour up.’ Gwaine snickered quietly, anger flashing across Arthur’s face, but Merlin was quicker. She stamped down on his foot, the Knight yelping.

‘One more sound from you, and I’ll turn you into a toad.’ She threatened, very seriously, before moving to Arthur’s side.

‘Let’s get you out of the armour.’ Merlin had been in Arthur’s service ever since she arrived in Camelot, acting as the manservant to the Prince. Uther hadn't been too keen on her being so close to Arthur, but Gaius provided a helpful lie about her being unable to bear children. That had been enough for her to keep the role, although she did have to obey to the man’s dress code. No dresses, no long hair.

Arthur’s reign had been different. Her hair was now long enough to braid, but Merlin stuck to the familiar tunics and neckerchiefs that suited her.

The armour was handed to Gwaine, who stumbled slightly under it, but didn’t complain. It left Arthur with very large clothing, a sword that didn’t quite suit her, and a mess of hair that Merlin would need to sort.

‘Sir Gwaine, would you mind going to find a suitable cave for us to stay in?’ He got the hint, leaving Merlin to undo the belt and remove Excalibur, before using Magic to shift the clothing to fit Arthur’s slimmer frame. It worked for the bottom half, sucking around skinnier thighs and curvy hips, but it proved to be a bad idea for her chest.

‘Gods.’ Arthur stated, staring in shock, and Merlin sniggered.

‘I’ve got a spare binder, hang on.’ Merlin rummaged through her bag, before pulling out the fabric. Arthur seemed less inclined to want to lose her shirt, eventually moving it over her head but keeping her back to Merlin.

The binder wrapped around, and Merlin quickly tied the lacings, before returning the shirt. Then she began to thread her fingers into Arthur’s hair, tugging it out of her eyes and back into a braid, tying it off with her neckerchief.

‘Not a word of this to anyone, Merlin.’ Arthur snapped, without the usual venom, but Merlin was too busy admiring her. 

A female Arthur was a stunning one. Smooth skin, bright eyes and the typical blonde hair that was beautiful.

‘I will turn you back, Arthur. You have my word.’ She promised, and Arthur straightened, nodding briefly.

‘Thank you, Merlin. We should probably catch up with Gwaine.’ Merlin agreed, grabbed the belt and wrapped it back around Arthur’s waist, Excalibur back safely by the King’s side.

**

Gwaine promptly decides that he is cursed. Dealing with Merlin every day, while pretending she isn’t the most beautiful woman in all of Albion? Hard.

Sitting watching the most beautiful woman in Albion tend to the second-most beautiful woman in all of Albion? Impossible.

To begin with, it’s completely fine. Arthur sits patiently while Merlin rattles on about different spells, lets her poke and prod and search for any mark the sorcerer might have left. Arthur has obviously decided that there is very little point in being modest, strips her shirt off and Gwaine averts his eyes.

‘So she’s not going to keel over?’ Gwaine asks Merlin, then realised he just dared to call the King of Camelot a girl. Arthur doesn’t correct him, so he figures it can’t be that bad.

‘Nope. The spell’s stable.’ Arthur grimaces, slumps in front of the fire and glares at Merlin like she’s somehow responsible for all of this. Like it wasn’t Arthur’s fragile masculinity that made him jump in front of Merlin, when she was perfectly capable of handling herself.

‘I’m having my furs and bedroll. You two can deal with yourselves.’ She snapped, reaching for her roll and lying down on it.

Gwaine watched as Merlin tended to the fire, handed Arthur her cloak like it was no issue. How the manservant remained so loyal, it was frustrating.

‘Arthur…’

‘What.’ The girl snapped, not bothering to roll over.

‘Don’t sleep in your binder, it’ll hurt.’ For a minute, Gwaine thought she was going to argue. But then Arthur sat up, took her shirt off for the second time, and waited.

‘I’ll get some more firewood.’ Gwaine decided, quickly leaving before the binder was lost.

When he returned, Merlin was cooking with what little food they had. She smiled up at him, patted the space beside her to sit. He did, nudging his knee against hers as they watched the fire crackle.

‘You’ve got this, Merls. If anyone can reverse the spell, it’s you.’ Her smile was practically radiating out, causing his own to quirk up. She was stunning, even sweaty and dirty from the ride.

‘I’m going to wash, I’ll brush the horses while I’m down there. Keep an eye on Arthur.’

‘I can hear you, idiot.’ Arthur grumbled from her spot, but Gwaine ignored her in favour of nodding to Merlin.

As soon as Merlin was gone, Arthur was sitting up. Her hair was already coming out of the braid, Merlin’s neckerchief abandoned.

‘You’re angry at me.’ Arthur concluded, head tilting to the side in the most amusing way.

‘You’re being a bitch to Merlin.’

‘I’m a bloody female!’

‘Like either of us care? You’re still the King. And in a couple of days, you’ll be back to your normal self. But Merlin will still be a girl, and everything you say against her sex will stand.’ He didn’t mean to snap at her, but watching the way Arthur’s face crumpled, he understood it had been needed.

‘I just… she makes it seem so easy.’

‘Because she’s Merlin.’ Gwaine said simply, and Arthur rose an eyebrow.

‘You love her.’ Like that was ever in doubt.

‘Obviously.’

A silent communication, an agreement that they would both treat Merlin with respect, and in return, Gwaine would assist Arthur.

**

Merlin shuddered, the cold was coming in quickly. The fire could only do so much, and with Arthur taking up most of the blankets they had brought with them, it left Merlin freezing. She looked around, spotted Gwaine slumped across the other side, his cape tucked over him.

‘Cold?’ He questioned, and Merlin nodded weakly. He offered an arm, and Merlin moved across to his side, hesitantly curled up against him.

Later, when the fire was dying down and the temperature was still dropping, Arthur broke the silence that had fallen in the cave.

‘Can… can I join? It’s cold.’ Merlin smiled, shuffled across to the King’s side and turning to Gwaine. He didn’t move for a moment, but Merlin was patient.

When he came across, it was to her side. She lay in the middle of them, stayed still when Arthur rolled over and wiggled closer.

‘This is cosy.’ She joked, and Arthur huffed, tucked her head under Merlin’s chin. An arm came out hesitantly, wrapping around her middle, before pausing.

‘You’re still wearing your binder.’ Normal Arthur would never have noticed. Would never have got this close.

‘I…’ She never took it off. Not when she was with the Knights, but now she hesitantly sat up. She reached for the cords, untied it and let it slip out from under her shirt, before returning to the mat that she had squished onto.

Gwaine let her come closer to his chest, his arm wrapping around her, and then including Arthur as well.

‘What happens on this trip…’ Arthur began, while Merlin looked across to her.

‘Stays on this trip.’ Gwaine grumbled, eyes already shut.

**

Arthur woke up when the sun was still hidden, blinking and sitting up slowly. Gwaine’s arm fell from her shoulder, Merlin muttering something under her breath and rolling towards the Knight. They were rather cute together, Arthur thought. He knew deep down that Gwaine cared for Merlin, had tried to ignore how that made him feel. Her feel. It was all too confusing, her head was a mess.

‘Arthur?’ Merlin had woken, which meant Gwaine was as well. She looked confused, dreary with sleep. Messy hair, lips that Arthur wanted to know the taste of.

What happens on this trip…

She moved slowly, let her head rest on Merlin’s chest and curled into her side. If her manservant was confused, she didn’t say anything, a hand coming to rest in her hair.

‘Arthur?’ The question wasn’t just her name, more wondering why she was being this affectionate. Still, Arthur had just been turned into a woman, and now was in a Cave for the next couple of days. Like this, maybe she could finally have what she wanted.

She looked to Gwaine first, silently conveying that she wasn’t stealing what was his. Then, Arthur propped herself up, looking down to Merlin. The Sorceress stayed still, even when Arthur slowly moved down, pressing her lips lightly to Merlin’s.

To begin with, nothing happened. The younger froze, and Arthur worried she’d overstepped.

Then she was kissing her back, gentle but insistent, a hand moving into her now-long hair and tugging. It felt good, different from being a man, but the fundamentals were the same. She still felt the blood rushing south, only this made her stomach twist until she was moving, straddling Merlin’s hips and reaching out with fingers that weren’t quite familiar.

When Arthur pulled back, sitting up straight, she found Gwaine watching them. Both of them.

‘Want to show Arthur what this new body can do, Merls?’ The sorcerer grinned, and before Arthur could even think to complain, she was on her back.

Merlin moved between her thighs, but any complaint Arthur had was silenced with a kiss. Hands skirting under her shirt, moving towards curves that Arthur was unsure of. Merlin didn’t hesitate, a hand closing over and fingers that pinched, Arthur gasping. It felt… different. A good different, and from the wicked smile on Merlin’s face…

She wanted control. Her eyes flicked open as Merlin’s head moved downwards, met Gwaine’s eye.

‘Merls, on your back.’ The Witch didn’t need to be told twice, vanished off of Arthur’s body without hesitating.

‘Want to learn what her mouth can do?’ Gwaine questioned, but his gaze didn’t leave Merlin. Clearly, he was waiting for her to say no to this. When Merlin made no move to stop the question, Arthur nodded. Her Knight reached out, rough hands slowly lifting Arthur’s shirt, then reaching for the belt.

‘Can I, Princess?’ Arthur nodded, the Knight stripping down her trousers and smallclothes quickly. Between her legs, unexplored territory that she knew how to please, but not from this angle.

‘Follow my lead.’ Gwaine smoothly interrupted her panic, guided Arthur back towards Merlin, who was patiently waiting.

She straddled her rather hesitantly, it all felt very… crude. But then Merlin’s hands were guiding her hips, and something warm was pressing against her…

‘Oh…’ She sighed, settling slightly as Gwaine’s hands moved down Merlin’s stomach, paused at her hips.

‘Merls?’

Arthur gasped when Merlin mumbled something that sounded like an affirmative, that damned tongue that Arthur usually scolded her for now finally being put to a good use. Tentatively, she rocked her hips, let her hands come to rest on Merlin’s tunic-covered chest.

‘Want it gone.’ Arthur stated, tugging at the fabric, and it vanished in an instant.

Magic. She usually didn’t get to observe it up close, but now it was happening right before her eyes, exposing Merlin’s chest to her.

Her manservant had curves. Beautiful, a perfect handful that Arthur reached for as she moved her hips against the Witch’s tongue. She looked to Gwaine, who had finished stripping Merlin’s trousers and smallclothes off. Long, thin legs were spread apart, Gwaine’s head ducking down between them.

This was like one of the stories her Knights told, when they were out on a Hunt or a Quest. Whispered talks of crude meetings, of things that happened in Taverns or Inns or in the lower parts of the City.

‘Shit, Merlin!’ She’d never admit that the Witch was good at this, but Arthur’s stomach was tightening, and it felt…

‘Two fingers between your thighs.’ Gwaine spoke up, lips slick and swollen and his fingers making an obscene sound from between Merlin’s legs. Whatever he was doing, it was causing Merlin to buck and squirm under the touch, and so Arthur had to conclude Gwaine knew what he was doing.

She dipped two fingers down, hesitantly pressed down.

Fuck.

She must have made a sound, because Gwaine was smirking and Merlin’s hands tightened on her hips, tongue hungrily moving faster. Arthur started rubbing hesitant circles onto the spot, moving her hips to the rhythm and groaning when Merlin’s tongue sped up. Hot, slick and too messy, and Arthur let her head fall back, before something snapped.

It wasn’t like being a man. The same rush was there, but it lasted for longer, drawn out into a wave that she could ride out using Merlin’s tongue as support.

Merlin’s demanding tongue-fucking turned to soft licks, Arthur withdrawing and rolling to the side, back onto the mat. Gwaine’s hand was speeding up, his kisses moving up Merlin’s body and towards her lips.

Arthur was content to watch, Merlin’s hands going for his belt and undoing it, before she got impatient and her eyes flicked gold.

Gwaine was handsome enough, she supposed. Her attraction wasn’t really to him, which was why she was glad that he had been more focused on Merlin.

‘Merls…’

‘Gwaine, c’mon. I want you.’ Clearly, this was the first time this had happened. Arthur wondered why, they seemed so close, perfectly attuned to each other. The way Gwaine traced her cheek, it was tender, gentle. Loving. And Merlin responded in the same way, kissed him hungrily and cradled his face.

‘Please.’ Merlin asked, and Gwaine nodded. His hips were moving, between her spread thighs, a hand holding himself steady. Arthur watched, mostly focused on Merlin’s expression, watching as her eyes rolled back and her thighs hooked to his hips, hands clutching at his shoulders.

‘Gods, Merlin, you’re so tight.’ Merlin’s response was a babbled mess, urging him on, and Arthur let a hand move between her thighs.

Wet, and not just from Merlin’s tongue, slowly parting her thighs and investigating the warmth.

‘Faster, oh gods, Gwaine!’ The Knight grunted, lips back against Merlin’s, a hand tracking down her stomach to the point where they were joined. It didn’t take much for Merlin’s back to arch up, for her toes to curl and her thighs to shake.

Gwaine pulled out, cock slick and eyes hungry, a hand on Merlin’s waist to encourage her to flip over. She did, pulled her knees up under her and spread her thighs, lowering her chest to the stone. It was a move Arthur had seen as Prince, with nobles and peasants alike, but never in such an alluring manner.

Her Knight, or maybe more accurately, Merlin’s Knight, stood no chance. He was lost, stumbling forward and pushing into her, hands on her hips.

The sound filled the cave, rhythmic slapping that was accompanied by Merlin’s gasps, breathy pleas for Gwaine to speed up, the Knight moaning her name like it was the very thing he needed to survive.

Gwaine had to be good, for Merlin was crying out for her second orgasm by the time Arthur had worked up to her own. She rocked onto two fingers, while Merlin slumped to the ground and Gwaine grunted, head tipped back and sweat shining off his chest as he emptied into her.

They collapsed in a pile, gentle hands and soft murmurs, and Arthur felt like she was intruding.

But then Merlin’s head rose, and her hand reached out.

‘Arthur, cuddles, c’mon.’ She went willingly, pressing to Merlin’s bare chest and glancing briefly to Gwaine. Was this just acceptable, because she was a girl?

‘We could do this again, you know. Once Arthur’s back to being Arthur.’ Gwaine’s gaze stayed on Arthur, even if he whispered the words into Merlin’s ear. The girl shuddered, then looked up shyly to Arthur.

‘I’d like that.’ The Witch said softly, and Arthur nodded.

‘So would I.’


End file.
